TWI391438B - Compositions comprising graft polymer for extrusion processing - Google Patents

Abstract

Molding materials (I) comprises thermoplastic homo-, co- or ter-polymer from styrene, alpha methylstyrene, core-substituted styrene, methylmethacrylate, acrylonitrile, methacrylnitrile, maleic acid anhydride and/or N-substituted maleimide; grafting polymer of e.g. styrene, alpha methylstyrene, core substituted styrene, methylmethacrylate and rubber; partially oxidized polyolefin; and alkaline earth metal oxides. Molding materials (I) comprises: (A) 5-95 wt.% (related to A+B) of at least a thermoplastic homo -, co- or terpolymer from styrene, alpha methylstyrene, core-substituted styrene, methylmethacrylate, acrylonitrile, methacrylnitrile, maleic acid anhydride and/or N-substituted maleimide or their mixtures; (B) 95-5 wt.% grafting polymer (related to A+B) of (B1) 5-90 parts per weight styrene, alpha methylstyrene, core substituted styrene, methylmethacrylate, acrylonitrile, methacrylnitrile, N-substituted maleimide or their mixtures, (B2) 95-10 parts per weight of at least a rubber at less than or equal to 10[deg]C which forms a partially cross linked particles with a median particle diameter (d 50) of 0.05-20 mm; (C) 0.05-5 parts per weight (per 100 parts of A+B) of at least a partially oxidized polyolefin; and (D) 0.005-2 parts per weight (per 100 parts of A+B) of at least one alkaline earth metal oxides (preferably magnesium oxide and calcium oxide). An independent claim is also included for molded bodies obtained by the extrusion of (I).

Description

Composition for extrusion processing comprising a graft polymer

The present invention relates to a molded composition comprising a graft polymer characterized by having very good processability by extrusion without the occurrence of some surface defects.

Plastics based on graft polymers, especially those of the ABS class, have been used for many years as engineering plastics for the manufacture of various types of mouldings (see eg Ullmann's Industrial Chemistry Encyclopedia, 5th edition, Volume A21). , pp. 652-653, VCH Press, Weinheim, 1992), a particular use for processing via injection molding or extrusion.

Depending on the type of processing, the molding composition used must comply with various requirements. For example, a molding composition comprising a graft polymer, which is intended to be processed by injection molding, must not cause any Mold scale (for this, see, for example, the solution to this problem described in EP 869147), and a molding composition comprising a graft polymer, which is intended for use in extrusion processors, must not be used in rolls Causes deposits on it.

A particular difficulty in extrusion processing is the formation of surface defects on extruded sheets, shaped objects, or blow molded or thermoformed parts, which are round or long in shape from about 0.5 to 20 mm in diameter. Defects.

Surprisingly, it has been found that the use of special additive mixtures results in a moulding composition comprising a graft polymer which has very good processability via extrusion without the occurrence of these surface defects.

The present invention provides a molding composition intended for extrusion processing comprising: A) from 5 to 95% by weight, preferably from 10 to 90% by weight, and particularly preferably from 20 to 75% by weight, At least one of the following thermoplastic-, co-, or terpolymers: styrene, alpha-methyl styrene, ring-substituted styrene, methyl methacrylate, acrylonitrile, methacrylonitrile, Maleic anhydride, N-substituted maleimide, or a mixture comprising the same, B) from 95 to 5% by weight (based on A+B), preferably from 90 to 10% by weight, and It is particularly preferred that it is from 80 to 25% by weight, at least one of the following graft polymers B.1) from 5 to 90 parts by weight, preferably from 20 to 80 parts by weight, and from 25 to 60 parts by weight. Partially preferred, styrene, α-methylstyrene, ring-substituted styrene, methyl methacrylate, acrylonitrile, methacrylonitrile, maleic anhydride, N-substituted maleimide Or a mixture comprising these, B.2) from the top to the bottom, from 95 to 10 parts by weight, preferably from 80 to 20 parts by weight, and particularly preferably from 75 to 40 parts by weight, at least One with one The glass transition temperature is ≦10 ° C rubber, and C) from 0.05 to 5 parts by weight, preferably from 0.1 to 3 parts by weight, and particularly preferably from 0.2 to 2 parts by weight (in each case, Based on 100 parts by weight of A+B), at least one partially oxidized polyolefin, and D) from 0.05 to 2 parts by weight, preferably from 0.08 to 1.5 parts by weight, and from 0.1 to 1 part by weight. Particularly preferred (in each case, based on 100 parts by weight of A+B), at least one alkaline earth metal oxide selected from the group consisting of magnesium oxide and calcium oxide.

Suitable thermoplastic polymers A) according to the invention are those comprising: styrene, alpha-methylstyrene, p-methylstyrene, vinyltoluene, halogenated styrene, methyl acrylate, methyl methacrylate, Acrylonitrile, maleic anhydride, N-substituted maleimide, or a mixture comprising these.

Polymers A) are similar to resins, thermoplastics, and rubber-free. Particularly preferred polymers A) are those comprising: styrene, methyl methacrylate, styrene/acrylonitrile mixtures, styrene/acrylonitrile/methyl Methyl acrylate mixture, styrene/methyl methacrylate mixture, acrylonitrile/methyl methacrylate mixture, α-methyl styrene/acrylonitrile mixture, styrene/α-methyl styrene/acrylonitrile mixture, Α-methylstyrene/methyl methacrylate/acrylonitrile mixture, styrene/α-methylstyrene/methyl methacrylate mixture, styrene/α-methylstyrene/methyl methacrylate/ Acrylonitrile mixture, styrene/maleic anhydride mixture, methyl methacrylate/maleic anhydride mixture, styrene/methyl methacrylate/maleic anhydride mixture.

Polymer A) is conventional and can be prepared by free radical polymerization, in particular via emulsion, suspension, solution, or bulk polymerization. The average molecular weight M _w is preferably from 20,000 to 200,000, and its intrinsic viscosity [η] is preferably from 20 to 110 ml / g (measured in dimethylformamide at 25 ° C).

The grafting monomers B.1) suitable for the preparation of the graft polymer B) are identical to those described for the polymer A).

The rubber B.2) which is particularly suitable for the preparation of the graft polymer B) is: polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, polyisoprene, or The C ₁ -C ₈ -alkyl acrylate is a base alkyl acrylate rubber, in particular: ethyl acrylate, ethyl hexyl acrylate.

If appropriate, the acrylate rubber may comprise up to 30% by weight (based on the weight of the rubber) of a copolymerized monomer such as vinyl acetate, acrylonitrile, styrene, methyl methacrylate, and/or vinyl ether. . The acrylate rubber may also comprise a relatively small amount, preferably up to 5% by weight, based on the weight of the rubber, of a cross-linking copolymerized ethylenically unsaturated monomer. Examples of the crosslinking agent are: alkylene glycol diacrylate and alkylene glycol methacrylate, polyester diacrylate, polyester methacrylate, divinylbenzene, trivinylbenzene, Triallyl cyanurate, allyl acrylate, allyl methacrylate, butadiene, or isoprene. The graft base may also be an acrylate rubber having a core/shell structure having a core comprising a crosslinked diene rubber comprising one or more conjugated dienes, such as polybutadiene, or a conjugate. A copolymer of a diene having an ethylenically unsaturated monomer such as styrene and/or acrylonitrile.

Examples of other suitable rubbers are those known as EPDM rubber (polymers comprising ethylene and propylene with a non-conjugated diene such as dicyclopentadiene), EPM rubber (ethylene-propylene rubber) and ruthenium The ketone rubber, if appropriate, may likewise have a core/shell structure.

Preferred rubbers B.2) for the preparation of the graft polymer B) are: diene rubber and alkyl acrylate rubber, and EPDM rubber.

The rubber B.2) is in the form of at least some degree of crosslinked particles, wherein the value of the particle diameter (d _{5 0} ) is from 0.05 to 20 μm, preferably from 0.1 to 2 μm, and from 0.1 to 0.8 microns is especially good.

The median particle diameter d _{5 0} is determined by ultracentrifuge measurements according to W. Scholtan et al., Kolloid-ZuZ Polymere, 250 (1972), pp. 782-796, or via electron microscopy.

The polymer B) can be obtained by free radical graft polymerization of the monomer B.1) in the presence of a rubber B.2) intended to be used as a graft base.

The preferred method for preparing the graft polymer B) is emulsion, solution, bulk, or suspension polymerization, and in combination with conventional methods including these methods, the ABS polymer is a particularly preferred graft polymer B).

Very good graft polymer B) is a product obtained by radical polymerization of a mixture of the following, and the use mixture comprises: styrene and acrylonitrile, preferably from 10:1 to 1:1 by weight, It is particularly preferred in a weight ratio from 5:1 to 2:1, and there is a rubber having a median particle diameter (d _{5 0} ) of from 100 to 450 nm, which mainly comprises a diene monomer to aggregate Butadiene is preferred, which may comprise up to 30% by weight of styrene and/or acrylonitrile acting as a comonomer, and very particularly preferred for the presence of two rubbers B.2.a) and B.2.b) Each having a median particle diameter (d _{5 0} ) from 150 to 300 nm and a median particle diameter (d _{5 0} ) from 350 to 450 nm, and which mainly includes diene monomers, in each case Preferred among them are polybutadiene which may contain up to 30% by weight of styrene and/or acrylonitrile as a co-monomer, and B.2.a):B.2.b) in a weight ratio of from 10: 90 to 90:10, preferably from 30:70 to 60:40.

The rubber content of the graft polymer B) is preferably from 40 to 95% by weight, particularly preferably from 50 to 90% by weight, and most preferably from 55 to 85% by weight.

Suitable partially oxidized polyolefins C) according to the invention are, for example, partially oxidized polyethylene and partially oxidized polypropylene, or partially oxidized polyethylene waxes and partially oxidized polypropylene waxes. Such compounds are known, for example, from: A. Thalhofer, Kunststoff-Handbuch [Handbook of Plastics], Book IV (Polyolefin), pp. 161-165 (Carl Hanser, Munich, 1969). Such compounds are commercially available and are generally named: polar polyolefin waxes, or polar polyethylene waxes, or polar polypropylene waxes.

Component D) used comprises: magnesium oxide, or calcium oxide, or a mixture comprising these.

The novel ABS composition may in principle comprise, in addition to the novel additive mixture C) + D), other additive components which improve processability.

Examples of such compounds are: long chain carboxyguanamine compounds such as: ethylenediamine distearylamine, mannosamine, ceramide, stearylamine, succinimide, lignite, long chain carboxylic acid Ester compounds, such as: glyceryl tristearate, glycerol trioleate, glyceryl tribehenate, glycerol tristearate, stearyl stearate, stearyl oleate , stearyl behenate, stearyl stearate, oleic acid ester, oleic acid ester, behenic acid oil ester, montanic acid oil ester, behenyl stearate, behenyl oleate, mountain Hawthorn phthalate, behenyl montelate, octyl stearate, isooctyl stearate, dodecyl stearate, lauryl oleate, glyceryl monostearate, di-hard Glyceryl citrate, glycerol monooleate, glycerol dioleate, pentaerythritol tetrastearate, pentaerythritol tetraoleate, pentaerythritol tetraammonium acetate, pentaerythritol tetraseuronate, three Pentaerythritol stearate, pentaerythritol trioleate, pentaerythritol tribehenate, pentaerythritol tri-seurorate, pentaerythritol monostearate, pentaerythritol monooleate , pentaerythritol monodecanoate, pentaerythritol mono- montanate, long-chain carboxylate compounds, such as: magnesium stearate, calcium stearate, zinc stearate, magnesium montanate, calcium montanate, zinc montanate, Magnesium behenate, calcium behenate, zinc behenate, magnesium oleate, calcium oleate, zinc oleate.

The novel molding composition is preferably a derivative which does not include the aforementioned long-chain carboxylic acid.

Very particularly novel molding compositions include: A) from 85 to 35 weight percent of a thermoplastic copolymer comprising: from 5 to 40 parts by weight of acrylonitrile, and from 95 to 60 parts by weight of styrene, alpha- Methylstyrene, acrylonitrile, N-phenylmaleimide, or a mixture comprising the same, B) from 15 to 65 wt% of a graft polymer, which is from 25 to 60 parts by weight of styrene , α-methylstyrene, acrylonitrile, N-phenylmaleimide, or a mixture comprising the same, above: from 75 to 40 parts by weight of polybutadiene, which may comprise Up to 30% by weight of styrene and/or acrylonitrile acts as a comonomer, and from a mixture of from 0.2 to 1.5 parts by weight (per 100 parts by weight of A+B), comprising: C) oxidized polyethylene wax, with D ) Magnesium oxide.

The novel molding composition comprising A), B), C), and D), if appropriate, with conventional additives such as processing aids, stabilizers, pigments, antistatic agents, fillers, The method comprises the steps of: mixing the individual components simultaneously or sequentially at room temperature or at a relatively high temperature, and then performing the melt compounding or melt extrusion at a temperature of 150 ° C to 300 ° C, Use conventional devices such as a closed mixer, an extruder, or a twin screw system.

The molding composition according to the present invention can be used to prepare a molding of any type, and can be extruded into a special method which can be used for the production of a molding using a conventional manufacturing method.

In principle, the novel molding compositions can also be processed via injection moulding.

The invention therefore also provides a method of preparing a molded composition, its use for the manufacture of a molded article, and a molded article obtained, and the present invention additionally provides an additive comprising C) and D) itself.

The invention is illustrated by the following examples.

Instance Thermoplastic resin A

The random styrene-acrylonitrile copolymer (weight ratio 72:28) had a _Mw of about 115,000 as determined by GPC (gel permeation chromatography).

Graft polymer B-I

The graft product obtained by the emulsion polymerization of the following is: 42% by weight of a styrene/acrylonitrile mixture (weight ratio of 73:27) above 58% by weight: comprising the following two kinds of microparticles a 1:1 mixture of diene (weight ratio) having: a) a median particle diameter (d _{5 0} ) of 290 nm, and b) a median particle diameter (d _{5 0} ) of 420 nm, The latex was agglomerated using a magnesium sulfate/acetic acid mixture, washed with water, and then dried in a vacuum.

Graft polymer B-II

The graft product obtained by the emulsion polymerization of the following is: 50% by weight of a styrene/acrylonitrile mixture (weight ratio of 73:27) having a median particle diameter (d _{5 0} ) at 50% by weight The 130 nm microparticles were placed on top of polybutadiene and treated as B-I.

Additive C:

Oxidized polyethylene: Licowax PED 191 (Clariant GmbH, Sulzbach, Germany)

Additive D:

Magnesium oxide The individual components were mixed in an extruder using the weight ratios stated in Table 1, together with 0.17 parts by weight of a phenolic antioxidant (Irganox 1076, Ciba Corporation), 0.30 parts by weight of a sulfur-containing synergist (Irganox PS 802, Ciba Corporation), with 0.15 parts by weight of an oxime oil.

The resulting material is then extruded using a Breyer BR 60 extruder with a 6-zone vent screw, screw diameter 60 mm, length 33D, melt pump, adjustment rod / adjustable The die of the lip, the width of 350 mm, the die 3 mm, the roller is a 3-roll calender placed vertically, and the plate is obtained. The temperature of the extruder was 240 ° C, the temperature of the die was 240 ° C, and the starting speed was 1.5 m / min, and in each case, the total extrusion time was 8 hours.

Observing the point at which the surface of the extrudate splits and begins to form a circular or elongated defect of about 0.5 to 20 mm. As can be seen from Table 1, only when a novel ABS composition is used, it is possible to achieve a long period of extrusion processing, and the surface of the extruded portion is not subjected to splitting.

Claims (9)

A molding composition comprising: A) a thermoplastic homo-, co-, or terpolymer of at least one of from 5 to 95% by weight, based on A+B: styrene, alpha-methyl Styrene, ring-substituted styrene, methyl methacrylate, acrylonitrile, methacrylonitrile, maleic anhydride, N-substituted maleimide, or a mixture comprising these, B) with A+ B is a reference, from 95 to 5% by weight of at least one of the graft polymers B.1) from 5 to 90 parts by weight of styrene, α-methylstyrene, ring-substituted styrene, methyl Methyl acrylate, acrylonitrile, methacrylonitrile, maleic anhydride, N-substituted maleimide, or a mixture comprising these, which is attached to the lower B.2) from 95 to 10 parts by weight At least one rubber having a glass transition temperature of ≦10 ° C, in the form of particles crosslinked at least to some extent, having a median particle diameter (d ₅₀ ) of from 0.05 to 20 microns, and C) based on 100 parts by weight of A+B, from 0.05 to 5 parts by weight of at least one partially oxidized polyolefin, and D) based on 100 parts by weight of A+B, 0.05 to 2 parts by weight of at least one alkaline earth metal oxide selected from magnesium oxide and calcium oxide. A molding composition comprising: A) a thermoplastic homo-, co-, or terpolymer of at least one of 10 to 90% by weight based on A+B: styrene, α-methyl Styrene, ring-substituted styrene, methyl methacrylate, acrylonitrile, methacrylonitrile, maleic anhydride, N-substituted maleimide, or a mixture comprising these, B) with A+ B is a reference, from 90 to 10% by weight of at least one of the graft polymers B.1) from 20 to 80 parts by weight of styrene, α-methylstyrene, ring-substituted styrene, methyl Methyl acrylate, acrylonitrile, methacrylonitrile, maleic anhydride, N-substituted maleimide, or a mixture comprising these, B.2) from 80 to 20 parts by weight At least one rubber having a glass transition temperature of ≦10 ° C, C) in each case, based on 100 parts by weight of A + B, from 0.1 to 3 parts by weight of at least one partially oxidized polyolefin, And D) in each case, based on 100 parts by weight of A+B, from 0.08 to 1.5 parts by weight of at least one alkaline earth metal oxide selected from magnesium oxide and oxidized . A molding composition according to claim 1 or 2, wherein A) is a copolymer comprising styrene and acrylonitrile. A molding composition according to claim 1 or 2, wherein B1) is a mixture comprising styrene and acrylonitrile. The molding composition according to claim 1 or 2, wherein B2) is a rubber having a median particle diameter (d ₅₀ ) of from 100 to 450 nm, which comprises polybutadiene, which may comprise At least one of styrene and acrylonitrile of up to 30% by weight acts as a comonomer. The molding composition according to claim 1 or 2, wherein B2) comprises two rubbers B.2.a) and B.2.b) each having a median particle diameter (d ₅₀ ) from 150 To a ratio of 300 nm to a median particle diameter (d ₅₀ ) from 350 to 450 nm, and a weight ratio of B.2.a):B.2.b) from 10:90 to 90:10, each Polybutadiene is included, which may comprise up to 30% by weight of at least one of styrene and acrylonitrile acting as a co-monomer. A molding composition according to claim 1 or 2 wherein D) is magnesium oxide. A sheet obtained by extruding a molding composition according to claim 1 or 2 of the patent application. A molding obtained by extrusion using a molding composition according to claim 1 or 2.